Reinforcing Qforms. How?

I got some Q logic Qforms for my Explorer used that need recovered an a plate inserted so I can install my speakers...whats the best way to reinforce these things so they are more ridgid and stronger? I have all kinds of dynamat laying around but I heard using fiberglass and clay can help? Whats the best way to secure these for best sound? Thanks!

Unless the drivers are designed to be sealed (most aren't) you won't get much midbass out of them.. You will have great imaging and good midrange. If you want midbass you can find drivers from 5" to 8" that can fit into your doors with little or no mods unless you want to build enclosres for them for your upfront bass or midbass.